1. Field of the Invention
This invention pertains generally to treatment of injuries of a skeletal joint and, more particularly, to systems, devices and methods for treatment of acute dorsal fracture dislocations of the proximal interphalangeal (PIP) joint in a finger.
2. Description of Related Art
Proximal interphalangeal joint fractures frequently have associated subluxations and/or dislocations of the middle phalanx with respect to the head of the proximal phalanx. Increasing degrees of joint injury are associated with increased degrees of joint instability. Injuries that feature dorsal displacement of the base of the middle phalanx on the head of the proximal phalanx frequently require skeletal fixation to obtain fracture and joint surface realignment. In addition, there are advantages with techniques that can obtain and maintain fracture and joint alignment by a dynamic force that will permit active range of motion while the bone and soft tissues heal. These active range of motion exercises (i.e., the patient's own muscles moving the injured joint through flexion and extension arcs of motion) serve to minimize joint stiffness and optimize the final result.
To achieve proper healing, a dynamic splint should maintain concentric joint reduction; specifically anatomic alignment of the articular base of the middle phalanx with respect to the head of the proximal phalanx such that rotation of the middle phalanx on the proximal phalanx occurs strictly about the anatomic axis of rotation of the PIP joint. When concentric joint reduction is not maintained, gliding motion between the intact dorsal base of the middle phalanx with respect to the head of the proximal phalanx is lost. The resultant rocking joint motion progressively destroys the articular joint cartilage, which produces pain, stiffness and increasingly severe degrees of traumatic arthritis.
One approach to addressing the foregoing concerns involves the use of what is referred to in the medical profession as a “force couple splint” which uses two Kirschner wires (“K-wires”) inserted transversely through the phalanxes in combination with a dorsal pin. In this approach, one K-wire is inserted through the middle phalanx, one K-wire is inserted through the proximal phalanx, and a dorsal pin is inserted into the middle phalanx. Once the K-wires are inserted, the protruding ends of both wires are bent at right angles in an interlocking arrangement, and an elastic band is deployed between the upturned ends of one K-wire and the exposed end of the dorsal pin. The “force couple” that is achieved by this construction is the combination of two coupled forces, one acting as a lever to the middle phalanx to urge the base of the middle phalanx in the palmar direction, and the other urging the distal end of the proximal phalanx in the dorsal direction.
While a “force couple splint” as described above provides a satisfactory solution, placement and insertion of the K-wires can be challenging for the surgeon. The placement and insertion procedure can be both complex and time-consuming, both of which are further considerations for which a solution is needed.